Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2024	Oct. 01, 2023	Sep. 29, 2024	Oct. 01, 2023
Earnings (Loss) per Share [Abstract]
Net income (loss) attributable to Minerals Technologies Inc.	$ 46.7	$ (19.2)	$ 113.1	$ 44.4
Weighted average shares outstanding (in shares)	32,100,000	32,500,000	32,200,000	32,500,000
Dilutive effect of stock options and deferred restricted stock units (in shares)	200,000	0	200,000	100,000
Weighted average shares outstanding, adjusted (in shares)	32,300,000	32,500,000	32,400,000	32,600,000
Basic earnings (loss) per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 1.45	$ (0.59)	$ 3.51	$ 1.37
Diluted earnings (loss) per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 1.45	$ (0.59)	$ 3.49	$ 1.36
Stock Options [Member]
Earnings (Loss) per Share [Abstract]
Options outstanding (in shares)	1,466,366	1,604,217	1,466,366	1,604,217
Anti-dilutive securities not included in computation of diluted earnings per share (in shares)	660,373	1,285,619	660,373	1,285,619